- Synonyms: Benzenethiol; Mercaptobenzene; Thiophenol
- OSHA IMIS Code Number: P105
- Chemical Abstracts Service (CAS) Registry Number: 108-98-5
- NIOSH Registry of Toxic Effects of Chemical Substances (RTECS) Identification Number: DC0525000
- Department of Transportation Regulation Number (49 CFR 172.101) and Emergency Response Guidebook: 2337 131
- NIOSH Pocket Guide to Chemical Hazards, Benzenethiol: chemical description, physical properties, potentially hazardous incompatibilities, and more
- American Conference of Governmental Industrial Hygienists (ACGIH) Threshold Limit Value (TLV) (2001): 0.1 ppm (0.45 mg/m3) TWA
- National Institute for Occupational Safety and Health (NIOSH) Recommended Exposure Limit (REL): 0.1 ppm (0.5 mg/m3) (15 Minutes) Ceiling (REL listed under Benzenethiol)
- Potential Symptoms: Irritation of eyes, skin, respiratory system; dermatitis; cyanosis; sore throat; cough, wheezing, dyspnea (breathing difficulty), pulmonary edema, pneumonitis; headache, dizziness, CNS depression; eye redness, pain, blurred vision; nausea, vomiting; kidney, liver, spleen damage
- Health Effects: Irritation – Eye, Nose, Throat---Marked (HE14); Offensive Odor (HE20)
- Affected Organs: Eyes, skin, respiratory system, CNS, kidneys, liver, spleen
- OSHA does not have a PEL for phenyl mercaptan.
- Phenyl mercaptan is listed by the FDA as a synthetic flavoring substance that is permitted for direct addition to food for human consumption (21 CFR 172.515).
- The inhalational LC50s in rats and mice were reported to be 33 ppm and 28 ppm, respectively, with most of the deaths at concentrations comparable to the LC50s occurring 2-15 days following a single 4-hour exposure to phenyl mercaptan.
- The NOAELs for developmental toxicity during gestation were 20 mg/kg/day and ≥40 mg/kg/day in rats and rabbits, respectively, when phenyl mercaptan was administered by oral gavage in corn oil. Phenyl mercaptan also had reproductive toxicity in rats with an indeterminate NOAEL, as the lowest-dose group (9 mg/kg/day) had increased liver and kidney weights, as well as microscopic changes in these organs.
- NIOSH Pocket Guide to Chemical Hazards: Benzenethiol.
- International Chemical Safety Cards (WHO/IPCS/ILO): Benzenethiol.
- Fairchild, E.J. and Stokinger, H.E.: Toxicologic studies on organic sulfur compounds. 1. Acute toxicity of some aliphatic and aromatic thiols (mercaptans). AIHA J. 19: 171-189, 1958.
- No authors listed: Reproductive Toxicity of Thiophenol II (CAS No: 108-98-5) Administered by Gavage to Sprague-Dawley Rats. NTP Report# RACB94001 [Abstract].
- No authors listed: Developmental Toxicity of Thiophenol (CAS No. 108-98-5) in Sprague-Dawley (CD®) Rats. NTP Study: TER92133 [Abstract].
- No authors listed: Developmental Toxicity of Thiophenol (CAS No. 108-98-5) in New Zealand White Rabbits. NTP Study: TER92134 [Abstract].
- Pohanish, R.P. (editor): Phenyl Mercaptan. Sittig's Handbook of Toxic and Hazardous Chemicals and Carcinogens, Fourth Ed., Vol. 2. Norwich, NY: Noyes Publications, William Andrew Publishing, 2002, pp. 1837-1839.
Date Last Revised: 03/16/2007
Monitoring Methods used by OSHA
Primary Laboratory Sampling/Analytical Method (SLC1):
- Coated Glass Fiber Filter (37mm Gelman Type A) Coating is 5% (w/v) mercuric acetate solution
- analytical solvent: 25% Hydrochloric acid
- maximum volume: 20 Liters
- maximum flow rate: 0.2 L/min
- current analytical method: Gas Chromatography; GC/FID
- method reference: OSHA Analytical Method (OSHA PV2075)
- method classification: Partially Validated
- note: Protect samples from light until analysis.
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